Lead, mercury and cadmium should not be used within the
factory. However, as part of many electric components, it is
very difficult to exclude their presence. In the food contact
area, electric components must always be enclosed in junction
boxes, casings, closed cable housings, cabinets, etc. or should
be installed in non-product contact zones or in technical corridors. Alloys for food contact may only contain aluminium,
chromium, copper, gold, iron, molybdenum, nickel, platinum,
silver, titanium, zinc, carbon, etc. However, zinc, copper, aluminium, bronze, brass, carbon and galvanized and painted steel
have poor resistance to detergents, disinfectants, acidic food and steam and
must be avoided in food contact areas.
Polytetrafluoroethylene, polyether-sulfone, polyvinylidene fluoride, phe-nol-formaldehyde, urea-formaldehyde,
melamine-formaldehyde, epoxy and
unsaturated polyester resins are used in
the construction of electric components, while other plastics like
polypropylene (PP), low-density polyethylene (PE), polyvinyl chloride
(PVC), polyurethane (PU), ethylene
propylene diene monomer (EPDM),
silicone, etc. are applied as jacket materials for electrical cables or for the construction of pneumatic hoses and
compressed air tubing. PP, PE and
PVC are also used to construct drain
pipes, while shields of polycarbonate can protect the food area
below light sources from shattered glass after accidental breakage of lamps. Silicone, nitrile, PU, EPDM and butyl rubber are
largely used as materials for gaskets, seals, etc. Epoxy is widely
used as floor, wall and ceiling coatings. Remember that many
plastics perform differently at - 25 °C than they do at 20 °C.
condensate from the system should be via an air break to prevent back-siphonage. Neither process nor utility piping should
have dead legs.
Like process piping, utility piping should be grouped to-
gether in easily accessible pipe trains whenever possible. The
points of use should also be grouped, in an attempt to mini-
mize individual ceiling drops. Vertical entrance of piping into
the equipment or equipment jacket is more hygienic than hori-
zontal utility piping runs. Running of process and utility piping
over open equipment in food preparation areas cannot be ac-
cepted, and nesting of ductwork should be avoided. Piping
should not clutter the ceiling. When
necessary, suspended racks that run
over a product zone shall be equipped
with a drip pan that protects the prod-
uct zone below and can be readily re-
moved for cleaning. Bumper guard
construction can also be installed in
heavy traffic areas to protect piping
from external mechanical forces.
Piping should be installed at least 6
cm from walls and floors to encourage
thorough cleaning around it. Piping in
corners should be avoided, as it ham-
pers thorough cleaning. Process equip-
ment shall be installed such that
enough space is provided to facilitate
pipe cleaning.
As piping (utility and process) can
affect or disrupt the airflow pattern in
zone H rooms, a fog test can control airflow patterns. The geo-
metry of the utility piping can destroy the desired air pattern
(e.g., piping with a square or rectangular profile is less favorable
than circular). Square and rectangular shapes create turbulence
and depressions where dust can accumulate, but cylindrical pro-
files make cleaning easier.
AREA.”
“THE LAYOUT AND ESIGN OF THE FOOD
FACTORY MUST BE
ADAPTED TO THE
HYGIENIC REQUIREMENTS
OF A GIVEN PROCESS,
PACKAGING OR STORAGE
Integration of Piping
Utility piping in technical corridors or zone H areas should
be integrated into wall compartments or the ceiling. If this is
not possible, it is recommended to use open racks, fixed to the
ceiling, or walls and columns close to the ceiling. However, sufficient clearance must be provided between pipe runs and adjacent surfaces so that both are readily accessible for cleaning
and maintenance. The pipe racks must be designed hygienically
to minimize the presence of horizontal ledges, crevices or gaps
where inaccessible dirt can accumulate.
Food processing support piping should be directly routed
from service rooms to process areas and should always be logical and simple. The amount of utility piping should be minimized and should have—like process piping—a slope of 1/200 to
1/100. Especially in process, hot water and process steam piping, standing “pools” of liquid that can support the growth of
microorganisms must be avoided. To remove condensate, steam
traps should be located at all low, convenient points along any
extended pipe length. Steam purges for relief of steam condensate in a drain should be closely connected to that drain. In
open systems, the steam vapor coming out of a drain can cause
humidity and odor problems within the factory. Discharge of
Piping that transports dirty fluids should not run in the
vicinity of or cross utilities that transport process aids, especially
if these process aids are in direct contact with the food to be
processed. Like process piping, food processing support piping
should run unidirectionally, with the support piping running
from the cleanest area toward the least clean areas. Support systems should deliver a certain process aid first in the process area
with the highest hygienic risk (zone H) and last in the zone of
lowest hygienic risk (zone L).
Pipeline penetration through walls, ceilings and floors
should be minimized, as holes in these areas can lead to sanitation problems and can invite the entry of insects and rodents.
Openings in floors for pipes should be guarded with a sleeve to
avoid spill of cleaning solutions onto a lower floor. When several pipes penetrate the floor, a larger curbed floor can replace
several pipe sleeves to improve the cleanability of the surrounding process environment. However, that curbed floor may create a large opening where pests may harbor, and where dirt,
water, etc. may accumulate. It must be a completely closed curb
with a cover that leaves no gap around the penetrating piping.
